Investigation of Material Effects in Knee Prosthesis Design Using Finite Element Method

Aim: Total knee arthroplasty (TKA) is an effective orthopedic intervention for patients experiencing significant pain and reduced mobility due to advanced joint degeneration. One of the most critical determinants of TKA success is the mechanical and biological properties of the implant materials used. The Finite Element Method (FEM) serves as a powerful engineering tool for modeling and analyzing the mechanical behavior of prosthetic components in detail. This study aimed to investigate the mechanical effects of different material combinations used in knee prosthesis design through FEM analyses. Material and Method: The mechanical behavior of three commonly used material combinations in knee prostheses—CoCr–UHMWPE, Ti–UHMWPE, and CoCr–Ti—was comparatively analyzed using the Finite Element Method (FEM). The geometry used in the FEM analysis was based on an anatomical knee model derived from computed tomography (CT) data. The 3D geometry was imported into ANSYS Mechanical APDL software, and adaptive meshing was applied to critical regions such as the femur–tibia contact area. The resulting models consisted of approximately 150,000 to 300,000 elements. Results: Combinations containing CoCr exhibit lower stress concentrations. The Ti–UHMWPE combination exhibits the highest deformation at 0.93 mm, while the CoCr–Ti combination presents the lowest displacement, reflecting its higher structural rigidity. The comparison between three materials indicates that the CoCr–UHMWPE combination offers the most balanced performance in terms of stress distribution, deformation, and contact pressure. Conclusion: The central finding of this study is that the CoCr–UHMWPE combination may represent the most optimal structure in terms of mechanical load distribution, contact stability, and deformation control in knee prosthesis applications. Although the Ti–UHMWPE configuration provides flexibility advantages, it must be cautiously evaluated for long-term structural stability. The CoCr–Ti configuration, while highly rigid, was shown to carry a potential risk of local stress-induced micro-damage.